8 Tiny Habits That Make You Happier

The old routine: Run through the phone-keys-wallet mental checklist.
The new habit: Add sunglasses to the list.
Why you'll be happier: Your mood and your facial muscles are linked—you've no doubt heard about the research showing that just forcing a smile improves your mood. Following that logic, squinting (which mimics the look you take on when you're mad as heck) can make you feel angry, says Daniele Marzoli, PhD, a psychologist at Italy's University of Chieti-Pescara, who adds that the effect is pretty much instantaneous. A pair of stylish sunglasses will solve the problem.